Thread-controlling mechanism for sewing-machines.



J. R. MOFFATT.

THREAD CONTROLLING MECHANISMYFOR SEWING MACHINES.

APPLICATION FILED AUG.8. I917.

Patented Nov. 19, 1918.

2 SHEETS-SHEET I m: "mull: runs :0. Pnaro L J. R. MOFFATT.

THREAD CONTROLLING MECHANISM FOR sewme MACHINES.

APPLICATION FILED AUG.8. 19H.

, Patented Nov. 19,1918.

2 SHEETS-SHEET 2.

' anism for Sewing-Machines,

JAMES R. MOFFA'IT, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION SPECIALMACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

THREAD-CONTROLLING MECHANISM FOR, SEWING-MACHINES.

To all whom it may concern:

Be it'known that 1, JAMES R. MOFFATT, a citizen of the United States,residing at Chicago, in the county of Cook, State of Illinois, haveinvented certain new and useful Improvements in Thread-ControllingMechof which the following is a description, referencebeing had to theaccompanyingdrawing, and to the figures of reference marked thereon.

' ;The invention relates to new and useful improvements in threadcontrolling mecha 'nisms for sewing machines and more particularly toathread controlling mechanism wherein a rotating member takes up andre-' leases thread and a releasing finger and a "check finger cooperatetherewith in per forming the thread controlling functions.

An object of the invention is to provide a detachable bracket forsupporting both the releasing finger and the check finger so that saidfingers may be assembled on the bracket and thebracket quickly attachedto a sewing machine or removed therefrom.

' ing'finger and the check finger, of the above" nmounted and saidbracket 1s capable of be- .ing quickly attached or detached from thefingers carried thereby,

for immediately supporting the same, parts being separated to show thestructure;

A further object of the invention is to provide a supporting bracket forthe releascharacter, and means whereby both the fingers maybe verticallyand simultaneously.

adjusted on said bracket, and independently adjusted horizontally.

A still further object of the invention is to providemeans whereby thecheck finger "may be angularly adjusted independently of the releasingfinger.

These and other objects wlll lnpart be obvious and will in part behereinafter more Figure 1 1s a vertical sectional View 7 through a partof a sewing machlne havlng my improvement attached thereto;

' Fig. 2 is a top plan view of the same;

Fig. 3 is a perspective View of the take-up cam, the operatingshafttherefor, the supporting bracket and the releasing and check theclamping screw for thebracket also being shown as separated from thebracket;

Fig. 4 is a perspective view of the releasing finger and check fingerand the devicles t e Specification of Letters Patent.

which show by way of Patented Nov. 19, 1918.

Application filed August 8, 1917. Serial No. 185,065.

Fig. 5 is a side view of the take-up cam and the thread fingers, showingthe thread just after it has been released from the shoulder of the camby the releasing finger and as held by the check finger.

My improvement is directed to a thread controlling mechanism which ispreferably used for the controlling ofv thelooper thread of a chainstitch sewing machine. The thread controlling mechanism, broadly, towhich the invention is applied is shown and described in the patentgranted to R. G. Woodward, November 27th, 1906, No. 836,849.

In said patent a rotary take-up cam operates to take up and release thelooper thread, and cooperating with this rotary take-up cam is avreleasing finger. which causes the thread to.be released from theshoulder of the take-up cam, and a thread finger which, for a certainperiod of time retains the thread after it is released from the shoulderof the take-up cam.

The present invention is directed particularly .tothe means forsupporting the thread fingers. Said invention consists broadly in adetachable bracket on which both the releasing finger and the checkfinger are sewing machine, carrying with it both the thread fingers.{The releasing finger is,

mounted for vertical adjustment in the bracket and may also be'adjustedendwise I bracket and is also endwise adjustable in its supportingmeans. 1

Referring more in detail to the drawings, I have shown part of thesewing machine consisting of a bed plate 1 which carries suitablebearings in which is mounted the main shaft 2. Mounted on this shaft isa take-up cam 3 consisting of two spaced disks k4. At each side of thetake-up cam is an arm 5 having a guide 6 for the looper thread. This armis carried by a movable support 7. The take-up cam 3 is provided with aconcentric thread retaining surface 8 and a non-concentric threadretaining surface 9. This non-concentric surface is disposedsubstantially radially of the cam and forms with the concentric surfacea shoulder 10. There is also a second non-concentric thread,retainingsurface 11. Cooperating with the take-up cam is a thread releasingfinger 12 and a check finger 13. These thread fingers extend between thedisks. The cam rotates in the direction of the arrow, as shown. inFig. 1. The non-concentric surface will engage the thread passingthrough the thread guides 6 andwill take up thread. The releasingfingerslides the thread outwardly along this surface 9 and over theshoulder 10. The thread is released from the shoulder 10 just as thelooper leaves the thread. loop and the position of the check finger 13determines the amount of slack in the looper thread when the needle isreaching lower end of stroke andprevious stitch is being set and lastneedle loops pull up. The surface 11 controls the looper thread whilethe looper is at rear end of stroke to prevent too much slack by abracket 14. This bracket 14 is secured to an upwardly extending lug orbearing 15 formed integral with the bed of the machine socket 17 inwhich is mounted the post 18.

Said post is adj ustably held in the socket by a set screw 19. The upperend of the post is provided with a head 20 which has a transverseopening to receive the shank of the thread releasing finger 12. Saidshank is adjustable endwise of the head and is held in adjusted positionby a set screw 21. Adjustably securedto the head 20 is a supportingbracket 22 for the check finger 13. Said head has a transverse opening23. The bracket 22 has a depending ear 24: formed with an opening 25. Ascrew 26 is adapted to pass through the opening 25 and into thetransverse opening Said screw is threaded into the opening in the headbut the bracket is free to turn on the screw. By tightening the screwthe bracket may be held in an adjusted position. Said bracket isprovided with an opening 27 for the shank of the check finger 13 and thecheck finger is adjustable endwise in this opening. A set screw 28serves as a means for clamping-the check finger in the bracket 22.

From the above description, it will be apparent that I have providedmeans for supporting the thread fingers which consistsv of a bracketadjustable so as to position the thread fingers properly between thedisks of the take up cam. Both thread fingers are carried on asupporting post and are verti- Cally adjustable so that the threadfingers may be adjusted to properly position the same for releasing thethread at the proper time. The releasing finger can also beadj ustedendwise in the supporting head there for and this together with thevertical adjustment of the releasing finger enables the releasing fingerto be set so as to forcethe thread over theshoulder 10 just at the righttime. The check finger may be angularly adjusted by shifting the bracket22 and: it

also has an endwiseadjustment. This anguplace when the post is raised.This enables the proper setting of the check finger so. that thenon-concentric portion 11 ofthe take up cam will pass the same attheproper time and the thread be released.

In the drawings, I have shown my :improved thread controlling mechanism.applied to the control of the looper thread of the sewing machine. Thelooper is indicatedat 29. The looper thread is indicated at 1. Thislooper moves transversely of .theline offeed. The feeding dogisindicated at 30 and the needles are indicatedat 31. There are twoneedles shown. i

It is obvious thatminor changes in the details of construction may bemade without departing from the spirit of the invention as set forth inthe appended claims.

Having thus described my invention, what,

I claim as new and. desire to secure by Letter's Patent, is

1. The combination of a take up cam having a thread. retaining surface,a releasing finger for releasing the thread fromsaid re taining surface,a check finger for holding the-threadafter it is released, a detachablebracket for supporting said releasing finger and'said check finger,means for supporting said releasing finger on saidbracket, where-Vv byit may be adjusted endwise thereon and means for supporting said checkfinger on said bracket, whereby it may be angularly adjusted and endwiseadjusted thereon. 5

2. The combination of a take up cam hav ing a thread retaining surface,a releasing finger for releasing the thread from said retaining surface,a check finger for holding the thread after it is released, a detachablebracket, means for supportingsaid releasingfinger on said bracket,whereby it may be 3. The combination of a take up cam having a threadretaining surface, a releasing finger for releasing the thread from saidretaining surface, a check finger for holding the thread after it isreleased, a bracket, a vertically adjustable post carried by saidbracket, means for supporting said releasing finger on said post wherebyit may be adjusted endwise thereon and means for supporting said checkfinger on said post whereby it may be angularly adjusted and endwiseadjusted thereon.

4. The combination of a take up cam having a thread retaining surface, areleasing finger for releasing the thread from said retaining surface, acheck finger for holding the thread after it is released, a bracket, avertically adjustable post carried by said bracket, said post having ahead at its upper end provided with an opening for the thread releasingfinger, said thread releasing finger 20 check finger may be adjustedendwise therein 25 and means whereby said second bracket may b angularlyadjusted on said post and held in adjusted positions.

In testimony whereof, I affiX my signature, in the presence of twowitnesses.

JAMES R. MOFFATT. Witnesses:

STEDMAN THOMAS, J. H. MASLAND.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

